Close cache file before renaming it

On Windows, calling os.Rename(oldpath, newpath) while `oldpath` is open will
not create `newpath`. So close `oldpath` before renaming it to avoid the creation
of a temporary cache file every time a command is run.

Author: tbillon

pkg/api/cache.go

@@ -239,12 +239,14 @@ func (c *ScalewayCache) Save() error {
 		if err != nil {
 			return err
 		}
-		defer file.Close()
+
 		if err := json.NewEncoder(file).Encode(c); err != nil {
+			file.Close()
 			os.Remove(file.Name())
 			return err
 		}
 
+		file.Close()
 		if err := os.Rename(file.Name(), c.Path); err != nil {
 			os.Remove(file.Name())
 			return err